Jet power plants of commercial subsonic transport aircraft are today widely predominantly so-called turbofan jet power plants. Such a turbofan power plant has a so-called core engine in which the actual combustion process of the kerosene is carried out. The core engine in a known manner has one or more compressor stages, a combustion chamber, and also one or more turbine stages in which the hot combustion gases yield some of their mechanical energy. This mechanical energy for one thing is required for driving the compressor stages, and for another thing a so-called turbofan, which is arranged upstream, is driven by the core engine and as rule has a significantly larger diameter than the core engine, and allows a considerable part of the air which flows through the power plant as a whole to bypass the core engine as so-called bypass airflow or secondary airflow. The turbofan makes up a significant part of the thrust power of the power plant via this bypass airflow, and in addition the high bypass airflow portion provides for a better environmental compatibility of the power plant, especially a better efficiency at subsonic speeds, and also an improved noise suppression of the hot exhaust gas flow of the core engine.
Jet power plants, during operation, are contaminated as a result of combustion residues of the core engine, and also as a result of air contaminants which are drawn in with the combustion or bypass air, such as dust, insects, saline fog, or other environmental contaminants. These contaminants especially also form a coating on the rotor blades and/or stator blades of the compressor of the core engine, which impairs the surface quality and, as a result, ultimately the thermodynamic efficiency of the power plant.
For removing the contaminants, jet power plants are cleaned. It is known from WO 2005/077554 A1 to arrange a multiplicity of cleaning nozzles upstream of the fan of a turbofan power plant for this purpose in order to thus clean the fan and the core engine.